1. Field of the Invention
The present invention relates to laser processing devices, and more specifically, to improvement of a laser processing device that processes a processing target by applying laser light.
2. Description of Related Art
A laser marking device is a laser processing device that processes a processing target (workpiece) by applying laser light, and characters, marks, figures, and the like can be printed on the workpiece by scanning an irradiation position of the laser light. In such a laser marking device, there is known a device in which the workpiece is photographed by a camera and check and adjustment of a processing position are carried out (e.g., Japanese Unexamined Patent Publication No. 2009-78280).
The laser marking device described in Japanese Unexamined Patent Publication No. 2009-78280 incorporates a camera for photographing the workpiece in a head housing, and carries out the check and adjustment of the processing position at high accuracy before the processing by making a light receiving axis of the camera coincide with an emission axis of the laser light.
This type of laser marking device has a head housing of a dustproof structure made from a light shielding member such as metal and accommodates, in the head housing, an optical system for emitting the laser light to prevent leakage of the laser light and to prevent degradation in performance due to the influence of dust and the like. Thus, the camera coaxial with the laser light axis described in Japanese Unexamined Patent Publication No. 2009-78280 is accommodated in such a head housing and hence cannot be attached/detached by a user, whereby the camera cannot be replaced.
In order to be able to replace the camera, the camera needs to be attached to the exterior of the head housing, and to this end, a camera opening for drawing out the light receiving axis of the camera to the exterior of the head housing needs to be provided in the head housing. However, if such a configuration is adopted, the laser light may be emitted from the camera opening as return light from the workpiece or scattered light by the optical system. For example, if the camera is detached during laser irradiation or if the laser irradiation is carried out without the camera being attached, the laser light may leak out to the exterior of the head housing.